and what is turn 1 at Sears Point like?...more to the point, how the track climbs the hill...is turn 2 invisible?
The most daunting venue you've ridden? Any that made you gulp and have second thoughts?
Orson, you're lucky I'm still awake.

The old turn 1 at Sears was a piece of cake. Hold it wide open and climb the hill. Please remember I was on an RZ350.
Turn 2 was a complete mystery until I spotted the paint marks the Bishop car racing school had painted on the track to help their students. Those were my markers. Otherwise, T2 is completely blind and it falls away as you go through it. Careful throttle is required on the exit, even on a 350.
At Sears the turn I had the most difficulty with was T4. Downhill decreasing radius with negative camber. I just kept Kenny Roberts' mantra in my head, "you'll never lose the front end if you're on the gas". It worked to a certain extent, but my scrotum still tightens up just thinking about it.
I loved the bit after T4 where you'd top the rise, catch some air, and dive into the carousel. If you know the track you know how to avoid the nasty dip at the bottom. Then you streak off down the drag strip.
Going through the esses is simple enough but back in the day we didn't have a chicane before T10. That thing was approached at full speed. Guess what? My bike siezed right in the middle of it. Two fingers on the clutch lever is a good thing.
Topping the hill after the Start/Finish line at Laguna for the first time is frightening, but once you establish your markers it becomes quite entertaining. The bike becomes almost weightless at the crest, but if you've done it right, it's pointed in the right direction and you wait for it to settle down and slam on the brakes for Andretti. The rest of the track is pretty straightforward except for the corkscrew. I've yet to settle that out, but I've only ridden the place once.